Inorganic n-type Bi₂Te₃ flexible thin film, as a promising near-room temperature thermoelectric material, has attracted extensive research interest and application potentials. In this work, to further improve the thermoelectric performance of flexible Bi₂Te₃ thin films, a post-electric current treatment is employed. It is found that increasing the electric current leads to increased carrier concentration and electric conductivity from 1874 S cm⁻¹ to 2240 S cm⁻¹. Consequently, a high power factor of ~10.70 μW cm⁻¹ K⁻² at room temperature can be achieved in the Bi₂Te₃ flexible thin films treated by the electric current of 0.5 A, which is competitive among flexible n-type Bi₂Te₃ thin films. Besides, the small change of relative resistance <10% before and after bending test demonstrates excellent bending resistance of as-prepared flexible Bi₂Te₃ films. A flexible device composed of 4 n-type legs generates an open circuit voltage of ~7.96 mV and an output power of 24.78 nW at a temperature difference of ~35 K. Our study indicates that post-electric current treatment is an effective method in boosting the electrical performance of flexible Bi₂Te₃ thin films.

Flexible Sb₂Te₃-based thermoelectric (TE) materials are promising candidates for fabricating energy devices that power wearable electronics and sensors. Enhancing the TE properties of Sb₂Te₃ thin films represents a significant scientific investigation. In this work, a thermal diffusion method is applied to prepare the In-doped Sb₂Te₃ thin film. In doping can lead to a high Seebeck coefficient of ~137.04 μV K⁻¹ as well as moderate electrical conductivity. As a result, the high power factor of ~18.22 μW cm⁻¹ K⁻² at 303 K is achieved. Moreover, In doping could reduce the thermal conductivity owing to the increase in phonon scattering. Finally, the high ZT values of ~0.47 at room temperature (303 K) and ~0.6 at 453 K are obtained. This indicates that In doping is a highly promising and effective approach to improving the TE performance of Sb₂Te₃ thin films.

Significant strides have been made in enhancing the thermoelectric properties of p-type PbTe alloys, whereas the thermoelectric performance of n-type alloys lags behind that of p-type alloys, primarily owing to the difficulty of improving their Seebeck coefficient via band convergence. In this work, Mn was introduced into the n-type Pb_0.985Sb_0.015Te alloy, and Mn doping increases the absolute value of the Seebeck coefficient significantly by increasing the effective mass and reducing carrier concentration, resulting in a higher power factor of 20.8 μW/K²cm being achieved for 0.5% Mn-doped sample at 573 K. Additionally, the decrease in electronic thermal conductivity, combined with the reduction in lattice thermal conductivity caused by the strengthened point defect scattering, leads to a significant decrease in the total thermal conductivity of the sample. And the lowest total lattice thermal conductivity of 1.16 Wm⁻¹K⁻¹ for a 2.0% Mn-doped sample has been achieved at 773 K. In the end, a maximum zT of 1.0 (773 K) and zT_ave of 0.62 (323–773 K) are attained in 1.0% Mn-doped Pb_0.985Sb_0.015Te alloy.